Fish Poisoning: A Problem in Food Toxication ALFRED F. BARTSCH and EARL F. McFARREN l INTEREST IN POISONOUS FISHES has intensified along the shores of a small bay in Japan, where greatly in recent years. World Wat II brought local people were poisoned by eating fish and many Americans and Europeans to tropical shellfish. Their affliction has been called Mina­ areas of the world where fish poisoning is com­ mata disease after the name of the bay. lrivesti­ mon. Also, interest in the welfare of native gation2 has shown the causative agent to be a populations of the Pacific islands has developed mercury compound accumulated in the tissues widely, and there is an impression that fish of the sea food. Mercury was reaching· the bay poisoning is increasing. In spite of an extensive as a component of waste?· discharged from a literature, there is considerable confusion on the vinyl chloride manufacturing plant. Remedial subject. waste handling measures recently installed at the Some marine organisms are dangerous be­ plant, coupled with a ban on fishing, have been cause of their venomous stings or bites, while fairly successful in curbing the number of·new others are poisonous to eat. Among the latter cases. are shellfish of several kinds, including mussels, Typical poisonous fishes are limited princi­ clams, and oysters. Some fin fishes also are poi­ pally to the warm seas lying mostly between 30° sonous to eat. They are intrinsically poisonous N. and 30° S. They are most numerous around and, like the toxic shellfish, do not produce their isolated islands far from continental shores, such undesirable effects through bacterial spoilage. as those of Micronesia, Melanesia, and Polynesia. Such fishes are the subject of this paper. The fish In the Caribbean, they are common around the poisoning problem is especially insidious be­ West Indies. cause of its inconsistencies. For example; a In spite of the numerous shore and reef fishes species is not always poisonous and therefore available as food in the tropic seas,potential summarily rejected; it may be eaten safely in toxicity is a deterrent to commercial harvest as some localities and not in others, or at some well as to use by native populations. Because times of year and not at others. Large specimens, recognition of poisonous specimens·presently otherwise attractive as food, are believed more requires tedious and time-consuming techniques, likely to be dangerous than smaller ones. a tremendous poundage of potentially useful fish Different from the usual fish poisoning epi­ cannot be brought to market nor used freely sodes is Haffs' disease noted among fishermen to meet the food needs of local populations. along the Baltic Sea coast of East Prussia and This problem is far from solution at the present at Lake Ysmen in Sweden (Schwimmer and time. Schwimmer, 1955). The more than a thousand HISTORY victims had consumed eels, eel livers, and a few other kinds of fish. Animals that ate the fish Existence of poisonous fishes became much also became ill and died. Selenium was once better known during World War II. They are thought to be involved in the etiology (Berlin, believed to have killed more than 400 Japanese 1948); toxic blue-green or other algae in the military personnel in Micronesia alone (Hal­ food chain of the fish have been suspected, also. stead, 1959). American military manuals warned Another atypical episode occurred recently against poisonous fishes, one (Smithsonian In- 1 Robert A. Taft Sanitary Engineering Center, Pub­ 2 Personal communication from Leonard T. Kur­ lic Health Service, Department of Health, Education, land, M.D., Dr. P. H., Chief, Epidemiology Branch, and Welfare, Cincinnati, Ohio. Manuscript received National Institute of Neurological Diseases and Blind­ February 21, 1961. ness, Public Health Service, Bethesda, Md. 42 Fish Poisoning-BARTsCH and McFARREN 43 stitution, 1944) stating: "All these fish [with Moray Eel Poisoning poisonous flesh} lack ordinary scales such as At Saipan during May of 1949 several Fili­ occur on bass, grouper, and sea trout. Instead, pinos captured a 6-ft. moray eel (Gymnothorax these poisonous fish are covered with bristles or flavimarginatus [Ruppel}) wnich they dressed, spiny scales, strong sharp thorns, or spines, or sliced into steaks, and cooked, including the are encased in a bony box-like covering. Some of head (Khlentzos, 1950). All 57 persons who these have naked skin, that is, no spines or scales. ate the fish became sick. After 3 days, 50 who Never eat a fish that blows itself up like a bal­ were bedridden and imable to talk were taken loon." Subsequent military literature has been on litters to the Saipan dispensary, and the revised in the light of more recent knowledge. sickest 17 of this group were moved by air to Nevertheless, some service men by mistake have the general hospital at Guam. Two died, one partaken of poisonous fishes, with painful result. after 14 days and the other after 20 days. In the A number of cases have been cited in the litera­ others, recovery was·prolonged, in some cases ture (Halstead, 1951, 1954). U. S. occupation taking 2 months or more. or trusteeship of many Pacific islands has em­ phasized to Americans the problem of poisonous Scombroid Poisoning fishes. In Hiroshima during the winter of 1953, Centuries ago, however, poisonous fishes al­ three households bought dried mackerel pike ready had made a mark in history. Captain Cook (Cololabis saira Brevoort), known locally as and several. officers of HMS "The Resolution" "samma sakuraboshi," from a peddler (Kawa­ almost ended their voyage in 1774 because they bata et al., 1955a). After broiling, the fish was were poisoned from eating a puffer obtained eaten by 11 persons, who within 21/2 hr. de­ from natives in New Caledonia (Courville et al., veloped flushing of the face and upper half of 1958). Down through the years many articles the body, palpitation, severe headache, dizziness, have been written by persons whose scientific and nausea. Fourteen outbreaks of this type of interests or economic pursuits have brought poisoning, involving 1,215 persons, occurred in them in contact with the problem. Their reports Japan during a 2-yr. period ending October of case histories invoke a healthy respect for 1954 (Kawabata et al., 1955a). In this fairly the dangers of fish poisoning. The following ex­ mild poisoning, victims commonly recover in a amples show why. day or less. Ciguatera STATUS OF FISH POISONING IN In May of 1956 in a rooming house at Fort THE MARSHALLS Lauderdale, Florida, a fine-looking 61/2-lb. bar­ Although many species of fishes known to be racuda (Sphyraena sp.) was taken from a deep poisonous occur in tropical areas, much atten­ freeze, where :it had been kept since capture the tion has centered on the Marshall Islands. Start­ day before, and prepared for the evening meal ing in 1924, Matsuo, a Japanese medical officer, (Paetro, 1956). It was served to five guests and studied the poisonous fishes at Jaluit Atoll for all of them became ill within 2 hr. Three of the a number of years (Matsuo, 1934). He listed victims were hospitalized. Recovery took from 2 36 of 180 species there as poisonous. In 1941, to 6 weeks, with symptoms persisting in one Hiyama studied the fishes at Jaluit and wrote a case almost 4 months. superbly illustrated report (Hiyama, 1943). At that time, other island groups in the Pacific Puffer Poisoning seemed little involved with fish poisoning, and At about the same time, a 65-year-old tour­ even now Jaluit is considered by some as the ist in south Florida ate the liver of a puffer center of the problem. (Sphraeroides testudineus Linnaeus) common in Scientific interest in the United States was the area (Benson, 1956). Symptoms appeared stimulated by outbreaks in the Line Islands in­ within 5 min. and the victim died 45 min. after volving 95 persons out of a population of 224. eating the fish. Subsequent studies by Halstead and his asso- 44 PACIFIC SCIENCE, Vol. XVI, January 1962 ciates (Halstead, 1959; Halstead and Bunker, to be slight. There appears to be no reciprocal 1954) led them to conclude that fish poisoning relationship between gastrointestinal illness and at Midway, Johnston, and the Line Islands rose fish poisoning, suggesting that the former had to a peak in 1947 and has since declined. As re­ stayed near its expected level and was not being centlyas 1958, how.ever, Marshallese of Majuro misdiagnosed as fish poisoning. However, paral­ and Jaluit atolls believed that fish poisoning lelism of the trend curves raises the question of was still increasing and expressed their concern whether fish poisoning may be mistaken for to the Trust Territory. As a result, an explora­ gastrointestinal illness. In August 19'57 Trust tory survey was made at request of Trust Terri­ Territory medinl personnel distributed a ques­ tory officials to accomplish several objectives, tionnaire to all atoll dispensaries in the Mar­ including the following: shalls. Use of this form identified the victim, 1. Define the extent of the fish poisoning described symptoms, treatment, and outcome, problem in the Marshall Islands (especially at and gave the name, origin, and mode of handling Majuro and Jaluit) in terms of human mor­ of the fish. It is believed that such information bidity, and other epidemiologic characteristics has not been available in the past to students available, in relation to the fishes involved and of the problem. Questionnaires for the area their toxicology. accessible to the hO$pital were selected as a com­ 2. Ascertain if poisonous fishes are currently parable group susceptible of analysis. The fol­ available in the area for human consumption.